Question

我想让我的ancestor query工作，但我一直收到这个错误：

BadQueryError：Parse Error：Identifier是符号的保留关键字 ANCESTOR

在这一行：

TweepleKey(twitter_handle))

我正在关注Using the Datastore教程（有效），但当我尝试将祖先查询的概念应用于我的代码（见下文）时，它会不断产生上述错误。我哪里出错了？

import cgi
import urllib
import webapp2
import cgi

from google.appengine.ext import db

# defines a data model for a geotweet
# GeoTweet model has 1 property: twitter_handle
class GeoTweet(db.Model):
    twitter_handle = db.StringProperty()
    date = db.DateTimeProperty(auto_now_add=True)


def TweepleKey(twitter_handle=None):
    # Constructs a Datastore key for a TweepleStore entity with twitter_handle
    return db.Key.from_path('TweepleStore', twitter_handle or 'default_handle')


class MainPage(webapp2.RequestHandler):
    def get(self):      
        self.response.out.write("""<html><body>""")
        twitter_handle = self.request.get('twitter_handle')

        tweeple = db.GqlQuery("SELECT * " 
                              "FROM GeoTweet " 
                              "WHERE ANCESTOR = :1 " 
                              "ORDER BY date DESC LIMIT 10",
                              TweepleKey(twitter_handle))
        for t in tweeple:
            if t.twitter_handle:
                self.out.write('<b>Found %s. Saved on %s.</b>' % (t.twitter_handle, t.date))
            else:
                self.out.write('<b>%s was not found!' % twitter_handle)

        self.response.out.write("""<form action="/search" method="post">
                    <div><textarea name="twitter_handle" rows="1" cols="20">@example</textarea>
                    <div><input type="submit" value="Find"></div>
                </form>         
            </body>     
        </html>""")



class TweepleStore(webapp2.RequestHandler):
    def post(self):
        twitter_name = self.request.get('twitter_handle')
        geotweet = GeoTweet(parent=TweepleKey(twitter_name))
        geotweet.twitter_handle = twitter_name
        geotweet.put()
        self.redirect('/?' + urllib.urlencode({'twitter_name': twitter_name}))


app = webapp2.WSGIApplication([('/', MainPage),
                            ('/search', TweepleStore)], debug=True)

Answer 1

GQL reference表示要使用WHERE ANCESTOR IS。

祖先查询解析错误

1 个答案: